"Those cities are thriving right now and that's the reason that our GDP is substantially higher than the rest of the nation's," Newsom said on Tuesday.

Newsom was reacting to Trump's comments to Fox News that the homeless situation in Los Angeles and San Francisco was "disgraceful" and suggested he might intervene to clean things up.

At the same time, Newsom said no one is in denial that homelessness in California is becoming a more severe problem.

San Francisco's transient population spiked 17% over the past two years according to the most recent homeless census; L.A.'s homeless population went up 16% over the past 12 months.

Rather than helping, Trump's intervention so has amounted to cutting programs for the homeless, Newsom said.

"He is substantially cutting the [the Department of Housing and Urban Development> budget, housing voucher budget, increasing defense and wall funding and decreasing the social safety net to address the reasons people are on streets and sidewalks in the first place," Newsom said.